“Thirty pounds will do a big difference in anybody’s body,” Lynch said. “I feel a lot better coming off the ball. I have a lot more wind. I’m not as tired as I used to be. Definitely a change.”

Shanahan said on Monday he was impressed with Lynch’s efforts over the summer and urged the importance of continuing such dedication. He will utilize his new slimmed down physique in the shift to the LEO position in Robert Saleh’s defense.

Lynch isn't the only player who has tailored his body to fit San Francisco's new defense. The team's defensive personnel up front appears to be well-equipped for the 4-3 system.

“We’ve put in a lot of work in the weight room,” Lynch said. “The power hasn’t gone anywhere. We do have to play a lot faster in our defense. People have shed the weight. I think we’ve all shed weight, but we haven’t lost any power.”

Over the last three seasons, Lynch has totaled 14 sacks, 74 tackles and seven passes defended. He missed part of 2016 due to a suspension and an ankle injury. But so far this offseason, Lynch looks to be a different player.

The linebacker has had several sacks over the first four practices of camp and even recorded an interception on a tipped pass. Lynch is just one of many defenders who have stood out so far.

“These guys upfront for us are something special,” quarterback Matt Barkley said. "I hope they’re doing that five times a game against the opponents we play. We’re learning to deal with that. It is a positive that they’re on our team.”